The purpose of this study is to determine whether sleep deprivation causes an increase in activity of the nervous system such that heart rate and blood pressure are elevated and to assess the responses of the nervous system, heart rate and blood pressure after sleep deprivation. Prior studies have shown that patients with sleep apnea have a predisposition to developing hypertension. It is possible that the development of hypertension is due to the elevated sympathetic nerve activity which these individuals have been shown to possess. The sleep deprevation resulting from the sleep apnea may be a casual factor in the elevated sympathetic nerve activity and play a role in the development of the hypertension.